Prediction of Closure Bolt Loads in Small Pressure Vessels: NUREG/CR-6007 vs. Detailed Finite Element Analysis

Author(s):  
Charles A. McKeel

Closure bolt loads in a flanged cylindrical containment vessel under internal pressure are determined by detailed Finite Element Analysis (FEA) and compared to values determined using NUREG/CR-6007 equations. The containment vessel is of small diameter with an inwardly dished bolted head that geometrically contrasts with the large, flat lidded casks which the NUREG addressed. The comparison showed a significant difference in the magnitude of pressure driven prying load between the FEA model and the NUREG approximate equations. This difference affected the predicted pressure that overcomes preload, and the rate of load increase after preload was exceeded. The difference was likely due to the contrasts between this vessel’s closure shape compared to the more typical flat cask lid shape used in the NUREG development.

Author(s):  
Daniel H. Suchora ◽  
Harry S. Perrine ◽  
Bradley Chamberlain

Abstract An electric powered Hot Metal Ladle Car was designed to safely transport a ladle filled with 160 metric tons of molten steel. The ladle geometry and space constraints within the use environment were specified. A final design was prepared and documented which met the design requirements and could be efficiently manufactured. An initial design was developed using past designs of a similar nature as a basis. By hand stress calculations were performed and the design modified to get stress values to acceptable levels. Preliminary design drawings were developed. At this stage of the design, some engineering personnel felt that the “by hand” stress analysis was sufBciently accurate to go ahead with fabrication. After much discussion it was decided to perform a Finite Element Analysis (FEA) to verify the design stresses calculated “by hand”. The FEA analysis predicted stresses that were significantly higher than indicated “by hand” in some critical change of section regions. These stress levels were much higher than the allowable stresses for this design. The difference between the FEA stresses and “by hand” stresses were evaluated. After much discussion and thought an insight to the actual load flow was developed which was consistent with the FEA results. With this insight, modifications were made to the design and incorporated into the FEA model. These changes needed to be practical from a manufacturing and end use viewpoint. After a few iterations on the design tire FEA stresses were reduced to an acceptable level. These changes were incorporated into the design. The final design of the ladle car was fabricated. The design was significantly improved due to the ability to accurately calculate stresses in transition regions of the frame where “by hand” methods were not really applicable. The combination of “by hand” methods to ballpark a design and FEA methods to reftne a design proved to be a powerful method to get a truly good design.


1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.


2012 ◽  
Vol 538-541 ◽  
pp. 3253-3258 ◽  
Author(s):  
Jun Jian Xiao

According to the results of finite element analysis (FEA), when the diameter of opening of the flat cover is no more than 0.5D (d≤0.5D), there is obvious stress concentration at the edge of opening, but only existed within the region of 2d. Increasing the thickness of flat covers could not relieve the stress concentration at the edge of opening. It is recommended that reinforcing element being installed within the region of 2d should be used. When the diameter of openings is larger than 0.5D (d>0.5D), conical or round angle transitions could be employed at connecting location, with which the edge stress decreased remarkably. However, the primary stress plus the secondary stress would be valued by 3[σ].


2015 ◽  
Vol 741 ◽  
pp. 223-226
Author(s):  
Hai Bin Li

The performance of automobile drive axle housing structure affects whether the automobile design is successful or not. In this paper, the author built the FEA model of a automobile drive axle housing with shell elements by ANSYS. In order to building the optimization model of the automobile drive axle housing, the author studied the static and dynamic performance of it’s structure based on the model.


2002 ◽  
Vol 124 (2) ◽  
pp. 189-199 ◽  
Author(s):  
Y. B. Guo ◽  
C. R. Liu

A practical explicit 3D finite element analysis model has been developed and implemented to analyze turning hardened AISI 52100 steels using a PCBN cutting tool. The finite element analysis incorporated the thermo-elastic-plastic properties of the work material in machining. An improved friction model has been proposed to characterize tool-chip interaction with the friction coefficient and shear flow stresses determined by force calibration and material tests, respectively. A geometric model has been established to simulate a 3D turning. FEA Model predictions have reasonable accuracy for chip geometry, forces, residual stresses, and cutting temperatures. FEA model sensitivity analysis indicates that the prediction is consistent using a suitable magnitude of material failure strain for chip separation, the simulation gives reasonable results using the experimentally determined material properties, the proposed friction model is valid and the sticking region on the tool-chip interface is a dominant factor of model predictions.


Author(s):  
Ajay Garg

Abstract In high pressure applications, rectangular blocks of steel are used instead of cylinders as pressure vessels. Bores are drilled in these blocks for fluid flow. Intersecting bores with axes normal to each other and of almost equal diameters, produce stresses which can be many times higher than the internal pressure. Experimental results for the magnitude of maximum tensile stress along the intersection contour were available. A parametric finite element model simulated the experimental set up, followed by correlation between finite element analysis and experimental results. Finally, empirical methods are applied to generate models for the maximum tensile stress σ11 at cross bores of open and close ended blocks. Results from finite element analysis and empirical methods are further matched. Design optimization of cross bores is discussed.


2020 ◽  
Vol 2020.28 (0) ◽  
pp. 104
Author(s):  
Riku SUZUKI ◽  
Noboru KATAYAMA ◽  
Kiyoshi DOWAKI ◽  
Shinji OGIHARA

1999 ◽  
Author(s):  
Richard B. Englund ◽  
David H. Johnson ◽  
Shannon K. Sweeney

Abstract A finite element analysis (FEA) model of the interaction of a nut and bolt was used to investigate the effects of sliding, friction, and yielding in a bolted connection. The finite element model was developed as a two-dimensional, axisymmetric system, which allowed the study of axial and radial loading and displacements. This model did not permit evaluation of hoop or torsional effects such as tightening or the helical thread form. Results presented in this paper include the distribution of load between consecutive threads, the relative sliding along thread faces, and the stress distribution and regions of yielding in the model. Finally, a comparison to previous, linear analysis work and to published experimental data is made to conclude the paper.


Author(s):  
Satoshi Nagata ◽  
Shinichi Fujita ◽  
Toshiyuki Sawa

There are two types of combination between external and internal threads used in threaded pipe connections for pressure piping specified in industrial standards like JIS as well as ISO. One is the combination that taper external thread of pipe is engaged with taper internal thread of a fitting. The other is that taper external thread of pipe is engaged with parallel internal thread of a fitting. Taper thread is always used for external thread outside the pipe wall. Both taper thread and parallel one are applicable to internal thread inside the fittings. This paper evaluates the mechanical behaviors of threaded pipe-socket joints (or pipe-coupling joints) and the difference due to the thread type combinations by means of axisymmetric finite element analysis for 3/4” and 3” joints. The analysis shows that the taper-taper threads combination establishes the full-length contact over the engaged threads but the taper-parallel has only a pair of threads in contact at the 1st engaged thread from the end of socket, and the difference results in the different behaviors of the joints. Stress and strain pattern also completely differ due to the difference in the engaged thread length. No significant effect of the size has been found in the present analysis for 3/4”and 3” joints. Experimental tightening tests and pressure leak tests have also been carried out for 3/4” and 3” joints with taper-taper threads combination. The measured experimental stress for 3/4” joints has shown an agreement with the simulated one fairly well. The pressure leak tests have demonstrated that the taper-taper threaded pipe-socket joints can hold internal pressure without leakage without using thread seal tape or jointing compound under low-pressure service condition. The 3/4” joints have started leaking at 1–4MPaG of internal pressure. The 3” joints haven’t shown leakage even at 6MPaG of internal pressure applied.


2016 ◽  
Vol 707 ◽  
pp. 154-158
Author(s):  
Somsak Limwongsakorn ◽  
Wasawat Nakkiew ◽  
Adirek Baisukhan

The proposed finite element analysis (FEA) model was constructed using FEA simulation software, ANSYS program, for determining effects of corrosion fatigue (CF) from TIG welding process on AISI 304 stainless steel workpiece. The FEA model of TIG welding process was developed from Goldak's double ellipsoid moving heat source. In this paper, the residual stress results obtained from the FEA model were consistent with results from the X-ray diffraction (XRD) method. The residual stress was further used as an input in the next step of corrosion fatigue analysis. The predictive CF life result obtained from the FEA CF model were consistent with the value obtained from stress-life curve (S-N curve) from the reference literaturature. Therefore, the proposed FEA of CF model was then used for predicting the corrosion fatigue life on TIG welding workpiece, the results from the model showed the corrosion fatigue life of 1,794 cycles with testing condition of the frequency ( f ) = 0.1 Hz and the equivalent load of 67.5 kN (equal to 150 MPa) with R = 0.25.


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